1. Field of the Invention
This invention relates to an electronic endoscope in which variations of a specific color component can be distinquished.
2. Related Art Statement
Various endoscopes (which shall be called electronic endoscopes in the present invention) have been developed in which a solid state imaging device, as a charge coupled device (CCD), are used.
One advantage of these electronic endoscopes is that the resolving degree is higher than a fiberscope. In addition, it is easier to record and reproduce picture images and picture image treatments such as the magnification of picture images. Thus, the comparison between two picture images is easier.
In the conventional television camera or the like, a luminance signal Y and color difference signals R-Y and B-Y are formed from imaged red (R), green (G) and blue (B) color signals. The luminance signal Y is treated in order to be enhanced in the image so as to improve the resolving degree of the picture quality. In the same manner, even the above mentioned electronic endoscopes have an enhanced image. For example, in an electronic endoscope of a field sequential system, the respective image enhanced amounts of the imaged R, G and B color signals have been enhanced the same amount.
However, if, as described above, only the luminance signal Y or each of the R, G and B color signals is enhanced by the same amount in the image, each color component will be equally enhanced in the image. Therefore, one problem that arises is, for example, when a specific color component which characterizes a deseased part is enhanced, color components other than this specific color component will also be enhanced in the image. Thus, the variation of this specific component will not be distinguished from the other color components and no sufficient diagnosis effect will be obtained.